Port FastCloneShallowArrayStub to ARM and x64.

src/x64/codegen-x64.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2477 matching lines @@
   // Load a writable copy of the function of this activation in a
   // register.
   frame_->PushFunction();
   Result literals = frame_->Pop();
   literals.ToRegister();
   frame_->Spill(literals.reg());
 
   // Load the literals array of the function.
   __ movq(literals.reg(),
           FieldOperand(literals.reg(), JSFunction::kLiteralsOffset));
-  // Literal array.
+
   frame_->Push(&literals);
-  // Literal index.
   frame_->Push(Smi::FromInt(node->literal_index()));
-  // Constant elements.
   frame_->Push(node->constant_elements());
+  int length = node->values()->length();
   Result clone;
   if (node->depth() > 1) {
     clone = frame_->CallRuntime(Runtime::kCreateArrayLiteral, 3);
+  } else if (length > FastCloneShallowArrayStub::kMaximumLength) {
+    clone = frame_->CallRuntime(Runtime::kCreateArrayLiteralShallow, 3);
   } else {
-    clone = frame_->CallRuntime(Runtime::kCreateArrayLiteralShallow, 3);
+    FastCloneShallowArrayStub stub(length);
+    clone = frame_->CallStub(&stub, 3);
   }
   frame_->Push(&clone);
 
   // Generate code to set the elements in the array that are not
   // literals.
   for (int i = 0; i < node->values()->length(); i++) {
     Expression* value = node->values()->at(i);
 
     // If value is a literal the property value is already set in the
     // boilerplate object.
@@ skipping 3734 matching lines @@
   // Return and remove the on-stack parameter.
   __ movq(rsi, rax);
   __ ret(1 * kPointerSize);
 
   // Need to collect. Call into runtime system.
   __ bind(&gc);
   __ TailCallRuntime(ExternalReference(Runtime::kNewContext), 1, 1);
 }
 
 
+void FastCloneShallowArrayStub::Generate(MacroAssembler* masm) {
+  // Stack layout on entry:
+  //
+  // [rsp + kPointerSize]: constant elements.
+  // [rsp + (2 * kPointerSize)]: literal index.
+  // [rsp + (3 * kPointerSize)]: literals array.
+
+  // All sizes here are multiples of kPointerSize.
+  int elements_size = (length_ > 0) ? FixedArray::SizeFor(length_) : 0;
+  int size = JSArray::kSize + elements_size;
+
+  // Load boilerplate object into rcx and check if we need to create a
+  // boilerplate.
+  Label slow_case;
+  __ movq(rcx, Operand(rsp, 3 * kPointerSize));
+  __ movq(rax, Operand(rsp, 2 * kPointerSize));
+  SmiIndex index = masm->SmiToIndex(rax, rax, kPointerSizeLog2);
+  __ movq(rcx,
+          FieldOperand(rcx, index.reg, index.scale, FixedArray::kHeaderSize));
+  __ CompareRoot(rcx, Heap::kUndefinedValueRootIndex);
+  __ j(equal, &slow_case);
+
+  // Allocate both the JS array and the elements array in one big
+  // allocation. This avoids multiple limit checks.
+  __ AllocateInNewSpace(size, rax, rbx, rdx, &slow_case, TAG_OBJECT);
+
+  // Copy the JS array part.
+  for (int i = 0; i < JSArray::kSize; i += kPointerSize) {
+    if ((i != JSArray::kElementsOffset) || (length_ == 0)) {
+      __ movq(rbx, FieldOperand(rcx, i));
+      __ movq(FieldOperand(rax, i), rbx);
+    }
+  }
+
+  if (length_ > 0) {
+    // Get hold of the elements array of the boilerplate and setup the
+    // elements pointer in the resulting object.
+    __ movq(rcx, FieldOperand(rcx, JSArray::kElementsOffset));
+    __ lea(rdx, Operand(rax, JSArray::kSize));
+    __ movq(FieldOperand(rax, JSArray::kElementsOffset), rdx);
+
+    // Copy the elements array.
+    for (int i = 0; i < elements_size; i += kPointerSize) {
+      __ movq(rbx, FieldOperand(rcx, i));
+      __ movq(FieldOperand(rdx, i), rbx);
+    }
+  }
+
+  // Return and remove the on-stack parameters.
+  __ ret(3 * kPointerSize);
+
+  __ bind(&slow_case);
+  ExternalReference runtime(Runtime::kCreateArrayLiteralShallow);
+  __ TailCallRuntime(runtime, 3, 1);
+}
+
+
 void ToBooleanStub::Generate(MacroAssembler* masm) {
   Label false_result, true_result, not_string;
   __ movq(rax, Operand(rsp, 1 * kPointerSize));
 
   // 'null' => false.
   __ CompareRoot(rax, Heap::kNullValueRootIndex);
   __ j(equal, &false_result);
 
   // Get the map and type of the heap object.
   // We don't use CmpObjectType because we manipulate the type field.
@@ skipping 2965 matching lines @@
   // Call the function from C++.
   return FUNCTION_CAST<ModuloFunction>(buffer);
 }
 
 #endif
 
 
 #undef __
 
 } }  // namespace v8::internal